Many analgesic/anti-inflammatory drug molecules such as Ampyrone, Azapropazone, Clofezone, Kebuzone, Metamizole, Mofebutazone, Oxyphenbutazone, Phenazone, Phenylbutazone, Phenylbutazone, Sulfinpyrazoneetc possesses pyrazolidine ring in the structure.
There is ample literature available on the preparation and evaluation of pharmacological activity of the compounds containing pyrazolidine scaffold. There is considerable research activity in progress for the synthesis and evaluation of the new molecules with pyrazolidine scaffold for various biological activities as well as novel methods of synthesis for achieving the same.
References may be made to Journal “Biochemical Pharmacology 70 (2005) 22-29”, wherein Inhibition of dipeptidyl peptidase IV by novel inhibitors with pyrazolidine scaffold is reported by HyaeGyeongCheonin.
References may be made to Journal, Bioorganic & Medicinal Chemistry Letters Volume 15, Issue 5, 1 Mar. 2005, Pages 1337-1340, wherein Jin Hee Ahn et al reported new series of pyrazolidine derivatives and their ability to inhibit dipeptidyl peptidase IV (DP-IV).
References may be made to U.S. Pat. No. 7,557,102, which discloses Pyrazolidine-1,2-dicarboxyldiphenylamide derivatives as coagulation factor Xa inhibitors for the treatment of thrombosis.
References may be made to Journal, Bioorganic & Medicinal Chemistry Letters, 2005, 15, 2527-2531 Kristina M. K. Kutterer et al discloses 4-alkyl and 4,4-dialkyl 1,2-bis(4-chlorophenyl)pyrazolidine-3,5-dione derivatives were synthesized, utilizing microwave accelerated synthesis, for evaluation as new inhibitors of bacterial cell wall biosynthesis.
References may be made to Journal J. Am. Chem. Soc., 2008, 130 (39), pp 12907-12911, wherein stereoselective Synthesis of cis- or trans-3,5-Disubstituted Pyrazolidines via Pd-Catalyzed Carboamination Reactions of unsaturated hydrazine derivatives is reported by Natalie C. The products obtained are reported to be in good yield with up to >20:1 diastereoselectivity.
In the light of the above, it is evident that the compounds having pyrazolidine ring possess valuable biological activities and therefore, it is essential to have an industrially viable process to synthesize the same on larger scale. As mentioned above, metal catalyzed reaction for the synthesis of Pyrazolidines are known, however, the same incurs higher cost and further affects the nature due to the pollution.